How did they get this answer?

Table 6.8 Production Prices Year 1 Year 2 Year 3 Year 1 Year 2 Year 3 Good X 40 50 80 $1.00 $1. 10 $1.20 Good Y 100 110 120 $0.50 $0.80 $1.00 40) Refer to Table 6.8. Assume that this economy produces only two goods Good X and Good Y. If year 1 is the base year, the value for this economy's real GDP in year 2 is: A) $90. B) $105. C) $115. D) $130. Answer: B